1 /* 2 * STMicroelectronics Key Scanning driver 3 * 4 * Copyright (c) 2014 STMicroelectonics Ltd. 5 * Author: Stuart Menefy <stuart.menefy@st.com> 6 * 7 * Based on sh_keysc.c, copyright 2008 Magnus Damm 8 * 9 * This program is free software; you can redistribute it and/or modify 10 * it under the terms of the GNU General Public License version 2 as 11 * published by the Free Software Foundation. 12 */ 13 14 #include <linux/module.h> 15 #include <linux/interrupt.h> 16 #include <linux/platform_device.h> 17 #include <linux/clk.h> 18 #include <linux/io.h> 19 #include <linux/input/matrix_keypad.h> 20 21 #define ST_KEYSCAN_MAXKEYS 16 22 23 #define KEYSCAN_CONFIG_OFF 0x0 24 #define KEYSCAN_CONFIG_ENABLE 0x1 25 #define KEYSCAN_DEBOUNCE_TIME_OFF 0x4 26 #define KEYSCAN_MATRIX_STATE_OFF 0x8 27 #define KEYSCAN_MATRIX_DIM_OFF 0xc 28 #define KEYSCAN_MATRIX_DIM_X_SHIFT 0x0 29 #define KEYSCAN_MATRIX_DIM_Y_SHIFT 0x2 30 31 struct st_keyscan { 32 void __iomem *base; 33 int irq; 34 struct clk *clk; 35 struct input_dev *input_dev; 36 unsigned long last_state; 37 unsigned int n_rows; 38 unsigned int n_cols; 39 unsigned int debounce_us; 40 }; 41 42 static irqreturn_t keyscan_isr(int irq, void *dev_id) 43 { 44 struct st_keyscan *keypad = dev_id; 45 unsigned short *keycode = keypad->input_dev->keycode; 46 unsigned long state, change; 47 int bit_nr; 48 49 state = readl(keypad->base + KEYSCAN_MATRIX_STATE_OFF) & 0xffff; 50 change = keypad->last_state ^ state; 51 keypad->last_state = state; 52 53 for_each_set_bit(bit_nr, &change, BITS_PER_LONG) 54 input_report_key(keypad->input_dev, 55 keycode[bit_nr], state & BIT(bit_nr)); 56 57 input_sync(keypad->input_dev); 58 59 return IRQ_HANDLED; 60 } 61 62 static int keyscan_start(struct st_keyscan *keypad) 63 { 64 int error; 65 66 error = clk_enable(keypad->clk); 67 if (error) 68 return error; 69 70 writel(keypad->debounce_us * (clk_get_rate(keypad->clk) / 1000000), 71 keypad->base + KEYSCAN_DEBOUNCE_TIME_OFF); 72 73 writel(((keypad->n_cols - 1) << KEYSCAN_MATRIX_DIM_X_SHIFT) | 74 ((keypad->n_rows - 1) << KEYSCAN_MATRIX_DIM_Y_SHIFT), 75 keypad->base + KEYSCAN_MATRIX_DIM_OFF); 76 77 writel(KEYSCAN_CONFIG_ENABLE, keypad->base + KEYSCAN_CONFIG_OFF); 78 79 return 0; 80 } 81 82 static void keyscan_stop(struct st_keyscan *keypad) 83 { 84 writel(0, keypad->base + KEYSCAN_CONFIG_OFF); 85 86 clk_disable(keypad->clk); 87 } 88 89 static int keyscan_open(struct input_dev *dev) 90 { 91 struct st_keyscan *keypad = input_get_drvdata(dev); 92 93 return keyscan_start(keypad); 94 } 95 96 static void keyscan_close(struct input_dev *dev) 97 { 98 struct st_keyscan *keypad = input_get_drvdata(dev); 99 100 keyscan_stop(keypad); 101 } 102 103 static int keypad_matrix_key_parse_dt(struct st_keyscan *keypad_data) 104 { 105 struct device *dev = keypad_data->input_dev->dev.parent; 106 struct device_node *np = dev->of_node; 107 int error; 108 109 error = matrix_keypad_parse_of_params(dev, &keypad_data->n_rows, 110 &keypad_data->n_cols); 111 if (error) { 112 dev_err(dev, "failed to parse keypad params\n"); 113 return error; 114 } 115 116 of_property_read_u32(np, "st,debounce-us", &keypad_data->debounce_us); 117 118 dev_dbg(dev, "n_rows=%d n_col=%d debounce=%d\n", 119 keypad_data->n_rows, keypad_data->n_cols, 120 keypad_data->debounce_us); 121 122 return 0; 123 } 124 125 static int keyscan_probe(struct platform_device *pdev) 126 { 127 struct st_keyscan *keypad_data; 128 struct input_dev *input_dev; 129 struct resource *res; 130 int error; 131 132 if (!pdev->dev.of_node) { 133 dev_err(&pdev->dev, "no DT data present\n"); 134 return -EINVAL; 135 } 136 137 keypad_data = devm_kzalloc(&pdev->dev, sizeof(*keypad_data), 138 GFP_KERNEL); 139 if (!keypad_data) 140 return -ENOMEM; 141 142 input_dev = devm_input_allocate_device(&pdev->dev); 143 if (!input_dev) { 144 dev_err(&pdev->dev, "failed to allocate the input device\n"); 145 return -ENOMEM; 146 } 147 148 input_dev->name = pdev->name; 149 input_dev->phys = "keyscan-keys/input0"; 150 input_dev->dev.parent = &pdev->dev; 151 input_dev->open = keyscan_open; 152 input_dev->close = keyscan_close; 153 154 input_dev->id.bustype = BUS_HOST; 155 156 error = keypad_matrix_key_parse_dt(keypad_data); 157 if (error) 158 return error; 159 160 error = matrix_keypad_build_keymap(NULL, NULL, 161 keypad_data->n_rows, 162 keypad_data->n_cols, 163 NULL, input_dev); 164 if (error) { 165 dev_err(&pdev->dev, "failed to build keymap\n"); 166 return error; 167 } 168 169 input_set_drvdata(input_dev, keypad_data); 170 171 keypad_data->input_dev = input_dev; 172 173 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 174 keypad_data->base = devm_ioremap_resource(&pdev->dev, res); 175 if (IS_ERR(keypad_data->base)) 176 return PTR_ERR(keypad_data->base); 177 178 keypad_data->clk = devm_clk_get(&pdev->dev, NULL); 179 if (IS_ERR(keypad_data->clk)) { 180 dev_err(&pdev->dev, "cannot get clock\n"); 181 return PTR_ERR(keypad_data->clk); 182 } 183 184 error = clk_enable(keypad_data->clk); 185 if (error) { 186 dev_err(&pdev->dev, "failed to enable clock\n"); 187 return error; 188 } 189 190 keyscan_stop(keypad_data); 191 192 keypad_data->irq = platform_get_irq(pdev, 0); 193 if (keypad_data->irq < 0) { 194 dev_err(&pdev->dev, "no IRQ specified\n"); 195 return -EINVAL; 196 } 197 198 error = devm_request_irq(&pdev->dev, keypad_data->irq, keyscan_isr, 0, 199 pdev->name, keypad_data); 200 if (error) { 201 dev_err(&pdev->dev, "failed to request IRQ\n"); 202 return error; 203 } 204 205 error = input_register_device(input_dev); 206 if (error) { 207 dev_err(&pdev->dev, "failed to register input device\n"); 208 return error; 209 } 210 211 platform_set_drvdata(pdev, keypad_data); 212 213 device_set_wakeup_capable(&pdev->dev, 1); 214 215 return 0; 216 } 217 218 static int keyscan_suspend(struct device *dev) 219 { 220 struct platform_device *pdev = to_platform_device(dev); 221 struct st_keyscan *keypad = platform_get_drvdata(pdev); 222 struct input_dev *input = keypad->input_dev; 223 224 mutex_lock(&input->mutex); 225 226 if (device_may_wakeup(dev)) 227 enable_irq_wake(keypad->irq); 228 else if (input->users) 229 keyscan_stop(keypad); 230 231 mutex_unlock(&input->mutex); 232 return 0; 233 } 234 235 static int keyscan_resume(struct device *dev) 236 { 237 struct platform_device *pdev = to_platform_device(dev); 238 struct st_keyscan *keypad = platform_get_drvdata(pdev); 239 struct input_dev *input = keypad->input_dev; 240 int retval = 0; 241 242 mutex_lock(&input->mutex); 243 244 if (device_may_wakeup(dev)) 245 disable_irq_wake(keypad->irq); 246 else if (input->users) 247 retval = keyscan_start(keypad); 248 249 mutex_unlock(&input->mutex); 250 return retval; 251 } 252 253 static SIMPLE_DEV_PM_OPS(keyscan_dev_pm_ops, keyscan_suspend, keyscan_resume); 254 255 static const struct of_device_id keyscan_of_match[] = { 256 { .compatible = "st,sti-keyscan" }, 257 { }, 258 }; 259 MODULE_DEVICE_TABLE(of, keyscan_of_match); 260 261 static struct platform_driver keyscan_device_driver = { 262 .probe = keyscan_probe, 263 .driver = { 264 .name = "st-keyscan", 265 .pm = &keyscan_dev_pm_ops, 266 .of_match_table = of_match_ptr(keyscan_of_match), 267 } 268 }; 269 270 module_platform_driver(keyscan_device_driver); 271 272 MODULE_AUTHOR("Stuart Menefy <stuart.menefy@st.com>"); 273 MODULE_DESCRIPTION("STMicroelectronics keyscan device driver"); 274 MODULE_LICENSE("GPL"); 275